363-206-295
Administration and Provisioning
8-34
Issue 1
December 1997
Dual Homed OC-3/OC-12 VT1.5 Path Switched
Ring (0x1)
8
Figure 8-5 is an example of an OC-3/OC-12 VT1.5 path switched ring (0x1) dual
homed application. This application is similar to the single homed application
except, for single homed 0x1 applications, both OC-12 function unit slots must be
equipped while, for dual homed 0x1 applications, one OC-12 function unit slot
must be empty (Node 5 slot 2 and Node 4 slot 1 in the example).
The DDM-2000 OC-12 ring supports ring (0x1) OC-3/IS-3 interfaces in its function
unit slots. These interfaces must be provisioned as ring (0x1). Signals pass
through the DDM-2000 OC-12 transport ring and exit to the DDM-2000 OC-3 ring.
OC-12 function unit slot fn(A)-1 of Node 5 is connected to OC-3 main-1 and
OC-12 function unit slot fn(A)-2 of Node 4 is connected to OC-3 main-2.
Protection switching is not done on the DDM-2000 OC-12 shelf for these lines or
paths on these lines. VT1.5 or STS-1 level path switching is done on the
DDM-2000 OC-3 Multiplexer shelf. In 0x1 operation, the OC-12 ring passes the
contents of the STS-1 time slots between the OC-12 high-speed line and the low-
speed OC-3/IS-3 lines without terminating or performing any line or path
protection switching on them.
Example Cross-Connections
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The OC-12 (STS level) cross-connections are:
■
At Node 4: mb-1:a-1
■
At Node 5: mb-1:a-1
The OC-3 (VT level) cross-connection is:
■
At Node 1: b-2-1:m-1-2-1
